1. So the half dome black alien object under the spare tire is the tuner?

2. I removed the MID and cd player to try to connect an EONON unit... when that experiment failed I reconnected the MID and cd at which time I may have forgotten to turn the key to the full off position... since then the MID is dead as in not even illumination.

1. No, the "alien object" directly under the dome is part of the SLS (self leveling system)...see illustration below. The radio tuner for those WITH the nav screen (BMW53/BM54) is located even further down...in front of the battery. But since you have the MID, the tuner is incorporated into the in-dash CD player...make sure the fuse in the rear harness of the CD unit isn't blown:

(radio tuner for those with onboard Nav (BM53/BM54) is located in front of battery on left side in pic below from Xoutpost)

2. If you disconnected/reconnected wiring harnesses with the ignition on...double check every fuse in the system front & rear (pull them out to visually check them...then push them back in if ok) that is connected with the audio/phone/obc/DSP (everything the MID receives data/info from). For example, for my 06...I'd check fuse #s 1,6,7,11,13,16,39,43,45,72,73,74,75...your fuses may be different, depending on build date...so check the front & rear fuse indexes for your vehicle:

(front fuse index is on drop down lid in glove box)

(rear fuse index is adhered to rear fuse box (on my 06)...may be adhered to panel or other area in rear)